JPH09197326A - Optical scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the accuracy of a reflection face from being deteriorated by the distortion of a rotary polygon mirror. SOLUTION: A coupling part 20 is formed on the tip side of a rotary shaft 12 an engaging hole 22 is formed on the coupling part 20. Slittings 20A are formed on the coupling part 20, so that cantilever pieces 20B of three divided parts of the coupling part 20 are easily bent. A circular fixing hole 38 is formed on the rotary polygon mirror 32 having plural reflection faces 34 and an elastic sheet 42 is arranged along the innerwall face of the fixing hole 38. The coupling part 20 of the rotary shaft 12 is inserted into the hole 38 and the cantilever pieces 20B of the coupling part 20 are pressed into the inner wall face parts of the hole 38 corresponding to corner parts 36. A fixed force generating member 26 is inserted into the hole 22 and the contilever pieces 20B of the coupling part 20 are respectively extended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical scanning device having an optical deflector, which is mounted on a laser printer or the like for use.

[0002]

2. Description of the Related Art A photoconductor in a charged state has a characteristic that when light is received, the potential of the part receiving the light is lowered. This characteristic is used in laser printers. In other words, laser printers that use a laser diode that emits a laser beam as a light source,
Conventionally, a rotating polygon mirror that is fixed to the rotation axis of a motor that is an optical deflector and is rotated by the motor deflects the laser beam and irradiates the laser beam on the photoconductor to form a latent image on the photoconductor. Was.

Therefore, the rotary polygon mirror needs to be securely fixed to the rotary shaft of the motor. As a conventional technique for fixing the rotary polygon mirror to the rotary shaft of the motor, for example, Japanese Patent Laid-Open No. 2-17.
0113 and Japanese Patent Laid-Open No. 2-293810 are known.

This Japanese Patent Laid-Open No. 2-170113 discloses
As shown in FIG. 11, there is shown a structure in which a tapered portion 114 is provided at the center of the rotary polygon mirror 112, and the tapered portion 114 is elastically pressed by a spring 116 while being fixed to a pedestal 120 of a rotary shaft 118. . In addition, JP-A-2-293810
As shown in FIG. 12, the publication discloses a structure in which a plurality of mounting holes 124 are provided in the rotary polygon mirror 122 and are fixed to a seat 130 of a rotary shaft 128 by a plurality of male screws 126.

[0005]

However, in such a conventional optical scanning device, heat generated by the pressure for fixing the rotary polygon mirror to the seat of the rotary shaft or by the high speed rotation of the optical deflector. The rotary polygon mirror and the rotary shaft are thermally expanded, which causes distortion in the rotary polygon mirror, and there is a drawback that the precision of the reflecting surface of the rotary polygon mirror finished with high accuracy deteriorates.

As described above, when distortion due to pressure, thermal expansion, etc. occurs in the rotating polygon mirror and the accuracy of the reflecting surface of the rotating polygon mirror deteriorates, even if the rotation is perfectly balanced, each reflecting surface of the rotating polygon mirror will be affected. The beam scanning position is deviated, and the image quality obtained by the optical scanning device is significantly deteriorated.

An object of the present invention is to provide an optical scanning device in which the precision of the reflecting surface is not deteriorated by the above-mentioned problem of distortion of the rotary polygon mirror.

[0008]

An optical scanning device according to claim 1, a rotary polygonal mirror having a plurality of mirror surfaces and having mounting holes formed therein, and a connecting portion provided with a slot on the tip side. , This connecting part is inserted into the mounting hole and is connected to the rotary polygonal mirror, and the connecting part is pressed against the rotary shaft of the motor that rotates the rotary polygonal mirror and the inner wall surface of the mounting hole in the radial direction of the rotary polygonal mirror. And a fixing force generating member for connecting the rotating polygonal mirror and the rotating shaft by causing the rotating polygonal mirror to generate a fixing force directed along the corner portion between the mirror surfaces of the rotating polygonal mirror.

In the optical scanning device according to claim 2 and the optical scanning device according to claim 1, the fixing force generating member is formed in a cylindrical shape, and the fixing force is formed in a fitting hole formed in the connecting portion of the rotating shaft. The generating member is inserted, and the fixing force is applied to the rotary polygon mirror as the outer peripheral surface of the fixing force generating member comes into contact with the connecting portion of the rotating shaft.

In the optical scanning device according to claim 3 and the optical scanning device according to claim 1, the fixing force generating member has a number of projections corresponding to the number of corners of the rotary polygon mirror, and the projections rotate. It is characterized in that a fixing force is generated by making contact with the connecting portions of the shafts.

An optical scanning device according to a fourth aspect of the present invention, a rotary polygon mirror having a plurality of mirror surfaces and having mounting holes formed therein, a sheet-like elastic member arranged along an inner wall surface of the mounting holes, and a slit. The rotating shaft of the motor that rotates the rotary polygon mirror with the connecting portion provided at the tip side and connected to the rotary polygon mirror with the elastic member sandwiched in the mounting hole The connecting part is pressed against the inner wall surface of the hole through the elastic member, and a fixing force is applied to the rotary polygonal mirror along the radial direction of the rotary polygonal mirror, in the direction of the corners between the mirror surfaces of the rotary polygonal mirror, thereby forming the rotary polygonal mirror. And a fixing force generating member that connects the rotating shafts.

The operation of the optical scanning device according to the first aspect will be described below. A mounting hole is formed in the rotary polygonal mirror having a plurality of mirror surfaces, and a connecting portion provided with a slit is arranged on the tip side of the rotary shaft of the motor, and the connecting portion is inserted into the mounting hole of the rotary polygonal mirror. It

In this state, the fixing force generating member presses the connecting portion against the inner wall surface of the mounting hole, and the fixing force generating member moves in the direction of the corner between the mirror surfaces of the rotary polygonal mirror along the radial direction of the rotary polygonal mirror. A fixed force is applied to the rotary polygon mirror to connect the rotary polygon mirror and the rotary shaft. Then, the motor rotates the rotary polygon mirror with the rotary shaft of the motor securely connected to the rotary polygon mirror.

Therefore, a fixing force is generated in the rotary polygon mirror along the radial direction of the rotary polygon mirror, which is the direction along the highly rigid portion of the rotary polygon mirror, in the direction of the corner between the mirror surfaces of the rotary polygon mirror. The distortion is less likely to occur in the rotary polygon mirror, and the precision of the reflecting surface of the rotary polygon mirror is kept good even at high speed rotation. Therefore, the scanning position of the beam does not shift for each reflecting surface of the rotary polygon mirror, and a high-quality image can be obtained.

The operation of the optical scanning device according to the second aspect will be described below. This claim operates similarly to claim 1. However, the fixing force generating member is formed in a cylindrical shape, and the fixing force generating member is inserted into the fitting hole formed in the connecting portion of the rotating shaft so that the outer peripheral surface of the fixing force generating member is connected to the rotating shaft. A fixed force is generated in the rotary polygon mirror as it abuts on the section.

Therefore, since the rotary polygon mirror and the rotary shaft can be connected with a simple structure in which the fixing force generating member is simply inserted into the fitting hole in the connecting portion, the manufacturing cost of the optical scanning device can be reduced.

The operation of the optical scanning device according to the third aspect will be described below. This claim operates similarly to claim 1. However, the fixing force generating member has a number of protrusions corresponding to the number of corners of the rotary polygon mirror, and the protrusions come into contact with the connecting portions of the rotary shaft to generate a fixing force.

Therefore, the fixing force generating member is arranged along the radial direction of the rotary polygon mirror in the direction of the corner between the mirror surfaces of the rotary polygon mirror only by arranging the respective projections so as to match the corners of the rotary polygon mirror. A fixed force is applied to the rotary polygon mirror to connect the rotary polygon mirror and the rotary shaft.

The operation of the optical scanning device according to the fourth aspect will be described below. This claim operates similarly to claim 1. However, the sheet-like elastic member is arranged along the inner wall surface of the mounting hole, and the connecting portion of the rotary shaft is inserted into the mounting hole,
The motor rotates the rotary polygon mirror with the connecting portion of the rotary shaft being connected to the rotary polygon mirror with the elastic member interposed therebetween.

Therefore, not only is the fixing force less likely to cause distortion in the rotary polygon mirror, but also the elastic member is sandwiched between the connecting portion and the rotary polygon mirror, so that the elastic member is elastically deformed by the strain due to thermal expansion. By absorbing, distortion due to thermal expansion can also be prevented.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An optical scanning device according to a first embodiment of the present invention is shown in FIGS. 1 to 5, and the present embodiment will be described based on these drawings.

A motor (not shown) constitutes the drive source of the optical scanning device 10 according to the present embodiment, and as shown in FIGS. 1 and 2, a disc-shaped motor is provided on the upper side of the rotary shaft 12 of the motor. A seat 14 is provided.

As shown in FIGS. 2 and 3, a positioning portion 16 for vertically positioning the rotary polygon mirror 32 is formed on the upper surface of the receiving seat 14 so as to project in an annular shape.
Further, a fitting portion 18 for horizontally positioning the rotary polygon mirror 32 is formed at the center of the upper surface of the receiving seat 14 so as to project upward in a cylindrical shape.

Further, the connecting portion 20 is annularly projected upward from the center of the upper portion of the fitting portion 18 of the receiving seat 14.
A connecting portion 20 is formed on the tip end side of the rotary shaft 12, and a fitting hole 22 is provided in the central portion of the connecting portion 20. Then, in the connecting portion 20, there are formed slits 20A that are vertically extending grooves at three positions at equal intervals along the circumferential direction of the connecting portion 20, and one piece of the connecting portion 20 is divided into three. The holding piece 20B is easily bent.

Further, the rotary polygon mirror 3 having a regular hexagonal shape having a plurality of reflecting surfaces 34 (six surfaces in this embodiment) which are mirror surfaces.
A circular mounting hole 38 that penetrates the rotary polygon mirror 32 in the up-down direction is formed in the center portion of the mounting hole 3.
An elastic sheet 42, which is a cylindrical and sheet-shaped elastic member, is arranged along the inner wall surface of 8. Further, at a position near the lower part of the mounting hole 38, a counterbore portion 38A formed in a circle larger than the mounting hole 38 so as to be fitted into the fitting portion 18 is provided.

Then, as shown in FIGS. 1 and 2, the connecting portion 20 of the rotary shaft 12 is inserted into the mounting hole 38. When the connecting portion 20 is inserted, the rotary polygon mirror 32 is abutted against the positioning portion 16 so that the positioning portion 16 positions the rotary polygon mirror 32 in the vertical direction, and at the same time, the spot facing portion 38A of the rotary polygon mirror 32 is positioned. The fitting portion 18 is fitted with a high precision tolerance to perform horizontal positioning.

At this time, the three slits 20A are arranged corresponding to the three corners 36 of the rotary polygon mirror 32 between the reflecting surfaces 34, and the cantilever 20B of the connecting portion 20 is the remaining three. It can be pressed against the portion of the inner wall surface of the mounting hole 38 corresponding to the corner portion 36 of the.

In the fitting hole 22 of the connecting portion 20, there is inserted a fixing force generating member 26 formed in a cylindrical shape by a metal material such as steel or aluminum or a resin material.

Here, the outer diameter of the fixing force generating member 26 is set to be slightly larger than the inner diameter of the fitting hole 22 of the connecting portion 20, and the fixing force generating member 26 is set to the fitting hole 22 of the connecting portion 20.
In the state in which the cantilever 20A is inserted therein, the cantilever piece 20B of the connecting portion 20 separated into three is pushed and spread in the radial direction by the fixing force generating member 26 together with the slit 20A.

Therefore, as shown in FIG. 2, when the fixing force generating member 26 presses the connecting portion 20 against the inner wall surface of the mounting hole 38, the connecting portion 20 strongly presses the inside of the mounting hole 38 through the elastic sheet 42. The fixing force P, which is pressed by the wall surface and is directed in the direction of the corner 36 between the reflecting surfaces 34 of the rotary polygon mirror 32 while being along the radial direction of the rotary polygon mirror 32, is generated in the rotary polygon mirror 32. That is, the rotary polygon mirror 32 in which the coupling portion 20 is inserted is positioned and coupled to the rotary shaft 12 by the force of pressing the coupling portion 20 against the rotary polygon mirror 32.

On the other hand, as shown in FIG. 4, the optical scanning device 10 includes a laser diode 52 for generating a light beam, and
A collimator lens 54 that collimates while passing the light flux emitted from the laser diode 52 is provided, and these serve as a light source. Further, on the optical axis of the laser diode 52, the rotary polygon mirror 32 is rotated in the direction of arrow A by the cylinder lens 56 and the motor.
And an f.theta. Lens 58 for condensing light is arranged between the rotary polygon mirror 32 and the cylinder lens 60 which sends the light deflected to the photoconductor 62.

That is, by driving the laser diode 52 in accordance with the image information signal, the laser diode 52 emits the laser beam L in accordance with the image information. The laser beam L emitted from the laser diode 52 passes through a collimator lens 54, a cylinder lens 56, and the like, and reaches a polygonal rotary polygon mirror 32 having a plurality of reflecting surfaces 34 on its side surface. And thousands to three
The rotary polygon mirror 32 is rotated at a high speed by a motor rotating at a rotation speed of about 0000 rpm to deflect the laser beam L. The laser beam L obtains a swing angle by the deflection of the rotary polygon mirror 32, and irradiates the photoconductor 62 which is rotated in the arrow B direction via the f.theta. Lens 58 and the cylinder lens 60 while scanning.

At this time, the f.theta.
The scanning speed on the upper side is corrected so as to be the same speed, and the deviation of the scanning position on the photoconductor 62 caused by the variation in the inclination of the reflecting surface of the rotary polygon mirror 32 is also corrected (also referred to as surface tilt correction).

A reflection mirror 64 for reflecting the laser beam L and a sensor 66 for receiving the laser beam L reflected by the reflection mirror 64 and detecting the position of the laser beam L are provided. This makes it possible to determine the scanning start timing.

A laser printer 60 using this optical scanning device 10 is shown in FIG. 5, and the operation of the laser printer 60 will be described based on this drawing.

A charger 72, a developing device 74, a transfer charger 76, and a cleaner 78 are arranged around the photoconductor 62. The rotating photoconductor 62 is charged by the charger 72, and the optical scanning device 10 causes the laser beam L to reach a position on the photoconductor 62 where the toner should be attached.
To reduce the potential.

Further, toner is attached only to the portion of the photoconductor 62 whose potential has changed in the developing device 74, and the transfer charger 7 is used.
6, the toner is transferred to the image carrier 80 such as a sheet conveyed in the direction of arrow C, and the image carrier 8 is fixed by the fixing device 82.
Melt and fix the toner on the surface of the toner.

After that, the toner remaining on the photoconductor 62 is removed by the cleaner 78, and the photoconductor 62 is charged again by the charger 72 and is exposed by the optical scanning device 10.

The operation of the optical scanning device 10 according to this embodiment will be described below. A mounting hole 38 is formed in the rotary polygon mirror 32, and a slot 20A is provided on the tip side of the rotary shaft 12 of the motor.
The connecting portion 20 provided with is arranged, and the connecting portion 20
Is inserted into the mounting hole 38 of the rotary polygon mirror 32.

In this state, the cylindrical fixing force generating member 26 is inserted into the fitting hole 22 formed in the connecting portion 20 of the rotary shaft 12, so that the outer peripheral surface of the fixing force generating member 26 is It contacts the connecting portion 20 of the rotary shaft 12. As a result, the fixing force generating member 26 presses the cantilever piece 20B of the connecting portion 20 against the inner wall surface of the mounting hole 38 so that the cantilever piece 20B of the connecting portion 20 faces the three corners 36 of the rotating polygon mirror 32, respectively. The reflecting surface 34 of the rotary polygon mirror 32 along the direction
The rotary polygon mirror 32 is connected to the rotary polygon mirror 32 by generating a fixing force P toward the three corner portions 36 therebetween. Then, the rotary shaft 12 of this motor is rotated by the rotary polygon mirror 3
2 is securely connected to the rotary polygon mirror 32.
To rotate.

Therefore, the fixing force P is applied in the direction of the corner 36 between the reflecting surfaces 34 of the rotary polygon mirror 32 along the radial direction of the rotary polygon mirror 32, which is the direction along the highly rigid portion of the rotary polygon mirror 32. Since it is generated, distortion is unlikely to occur in the rotary polygon mirror 32, and the accuracy of the reflecting surface 34 of the rotary polygon mirror 32 is kept good even at high speed rotation. Therefore, the scanning position of the laser beam L does not shift for each reflecting surface 34 of the rotary polygon mirror 32, and a high-quality image can be obtained.

Further, since the rotary polygon mirror 32 and the rotary shaft 12 can be connected with a simple structure in which the fixing force generating member 26 is simply inserted into the fitting hole 22 in the connecting portion 20, the manufacturing cost of the optical scanning device 10 is reduced. Is reduced.

Further, in this embodiment, the elastic sheet 4 is used.
2 are arranged along the inner wall surface of the mounting hole 38, and the rotary shaft 1
The motor rotates the rotary polygon mirror 32 in a state in which the second connection portion 20 is inserted into the mounting hole 38 and the connection portion 20 of the rotary shaft 12 is connected to the rotary polygon mirror 32 with the elastic sheet 42 interposed therebetween. become.

Therefore, the rotating polygon mirror 32 is fixed by the fixed force P.
Not only is it less likely to be distorted, but since the elastic sheet 42 is sandwiched between the connecting portion 20 and the rotary polygon mirror 32, even if the motor heats up and the connecting portion 20 expands due to heat,
The elastic sheet 42 elastically deforms and absorbs the strain due to thermal expansion, and the strain due to thermal expansion can also be prevented.

For example, the expansion of aluminum, which is generally used as the rotary shaft 12, due to the heat is from room temperature to 60.
Even if the temperature rises to ° C, since the amount is about 1.54 μm, the elastic sheet 42 having a thickness of about 0.5 mm is connected to the connecting portion 20.
If it is sandwiched between and the rotary polygon mirror 32, expansion due to heat can be absorbed.

Next, an optical scanning device according to a second embodiment of the present invention is shown in FIGS. 6 and 7, and the present embodiment will be described based on these figures. The same members as those described in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIGS. 6 and 7, the rotary polygon mirror 32 of the present embodiment has a quadrangular shape having four reflecting surfaces 34, and the connecting portion 20 has four rotary polygon mirrors 32. Four slits 20A are formed so that the cantilever pieces 20B are arranged so as to correspond to the one corner 36. On the other hand, the fixing force generating member 90 has a shape having four protrusions 90A, which is the same in number as the four corners 36 of the rotary polygon mirror 32.

Then, as shown in FIG. 6, the fixing force generating member 90 is attached to the fitting hole 2 of the connecting portion 20 so that the respective projections 90 A are arranged corresponding to the corners 36 of the rotary polygon mirror 32.
It will be pushed into 2.

The operation of the optical scanning device 10 according to this embodiment will be described below. The fixed force generating member 90 is the rotating polygon mirror 3.
The projections 90A are provided in a number corresponding to the number of the two corners 36, and the projections 90A respectively come into contact with the connecting portions 20 of the rotary shaft 12 to generate the fixing force P.

Therefore, the fixing force generating member 90 rotates in a direction along the highly rigid portion of the rotary polygon mirror 32 simply by arranging the respective projections 90A so as to match the corners 36 of the rotary polygon mirror 32. A fixed force P is generated in the rotary polygon mirror 32 in the direction of a corner 36 between the reflecting surfaces 34 of the rotary polygon mirror 32 along the radial direction of the polygon mirror 32 to connect the rotary polygon mirror 32 and the rotary shaft 12. become.

As described above, also in the present embodiment, as in the first embodiment, the rotary polygon mirror 32 is less likely to be distorted, and the precision of the reflecting surface 34 of the rotary polygon mirror 32 is good even at high speed rotation. To be kept. Therefore, the reflecting surface 3 of the rotary polygon mirror 32
The scanning position of the laser beam L does not shift for every 4,
High quality images can be obtained.

Next, an optical scanning device according to a third embodiment of the present invention is shown in FIGS. 8 and 9, and the present embodiment will be described based on these drawings. The same members as those described in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 8, the fixing force generating member 92 of this embodiment is the fixing force generating member 26 of the first embodiment.
The lid 92A is integrally provided on the upper part of the. Then, when the fixing force generating member 92 is inserted into the connecting portion 20, the shape becomes as shown in FIG.

By doing so, the fixing force generating member 9
The upper surface of the second lid 92A and the upper surface of the rotary polygon mirror 32 are aligned in the height direction. Therefore, it is possible to eliminate wind loss due to members such as springs and screws for fixing the rotary polygon mirror 32 as in the related art. Further, the outer shape of the lid portion 92A is set to the rotary polygon mirror 32.
By making the diameter larger than the diameter of the mounting hole 38, it is possible to obtain a fixing force in the height direction and prevent the rotary polygon mirror 32 from coming off the rotary shaft 12.

Next, an optical scanning device according to the fourth embodiment of the present invention is shown in FIG. 10, and the present embodiment will be described based on this drawing. The same members as those described in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 10, the fixing force generating member 94 of the present embodiment has a structure in which a male screw 94A is provided on the outer peripheral portion thereof, and the fixing force generating member 94 is a screw member.
As a result, the fixing force generating member 94 can be prevented from coming off from the connecting portion 20 by screwing the fixing force generating member 94 to the connecting portion 20.

The elastic sheet 42 employed in the above-described embodiment is not limited to the cylindrical shape, and the sheet is a plate-like sheet and the sheet-like sheet is partially sandwiched between the rotary polygon mirror 32 and the connecting member 20. It may or may not be necessary in some cases. Further, the number of slots and the number of surfaces of the rotary polygon mirror are not limited to those in the embodiment.

[0058]

As described above, according to the present invention, it is possible to prevent the rotary polygon mirror from being distorted due to the fixing force applied to the rotary polygon mirror or thermal expansion. Therefore, even if the operating temperature of the optical scanning device changes, variations in the scanning position of the beam can be suppressed, and a high quality output image can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic perspective view around a rotary polygon mirror of an optical scanning device according to a first embodiment of the present invention, showing a state before a fixing force generating member is inserted.

FIG. 2 is a cross-sectional view taken along the line 2-2 of FIG. 1, showing a state after the fixing force generating member has been inserted.

FIG. 3 is an exploded perspective view around a rotary polygon mirror of the optical scanning device according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram of an optical scanning device according to a first embodiment of the present invention.

FIG. 5 is a schematic diagram of a laser printer in which the optical scanning device according to the first embodiment of the present invention is adopted.

FIG. 6 is a plan view around a rotary polygon mirror of an optical scanning device according to a second embodiment of the present invention.

FIG. 7 is an exploded perspective view around a rotary polygon mirror of an optical scanning device according to a second embodiment of the present invention.

FIG. 8 is a schematic perspective view around a rotary polygon mirror of an optical scanning device according to a third embodiment of the present invention, showing a state before a fixing force generating member is inserted.

FIG. 9 is a schematic perspective view around a rotary polygon mirror of an optical scanning device according to a third embodiment of the invention, showing a state after a fixing force generating member is inserted.

FIG. 10 is a perspective view of a fixing force generating member of an optical scanning device according to a fourth embodiment of the present invention.

FIG. 11 is a schematic cross-sectional view around a rotary polygon mirror according to a first conventional technique.

FIG. 12 is an exploded perspective view around a rotary polygon mirror according to a second conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Optical scanning device 12 Rotating shaft 20 Connecting part 26 Fixing force generating member 32 Rotating polygon mirror 38 Mounting hole 42 Elastic sheet 90 Fixing force generating member 92 Fixing force generating member 94 Fixing force generating member

Claims (4)

[Claims] 1. A rotary polygonal mirror having a plurality of mirror surfaces and having mounting holes formed therein, and a connecting portion provided with a slot on the distal end side, and the connecting portion is inserted into the mounting hole for rotation. The rotation axis of the motor that rotates the rotary polygon mirror while it is connected to the polygon mirror, and the connecting part is pressed against the inner wall surface of the mounting hole, and the direction of the corner between the mirror surfaces of the rotary polygon mirror along the radial direction of the rotary polygon mirror. An optical scanning device, comprising: a fixing force generating member that generates a fixing force directed toward the rotating polygonal mirror to connect the rotating polygonal mirror to the rotating shaft. 2. The fixing force generating member is formed in a cylindrical shape, and the fixing force generating member is inserted into a fitting hole formed in the connecting portion of the rotating shaft to rotate the outer peripheral surface of the fixing force generating member. 2. The optical scanning device according to claim 1, wherein a fixed force is applied to the rotary polygonal mirror as it comes into contact with the connecting portion of the shaft. 3. The fixing force generating member has a number of projections corresponding to the number of corners of the rotary polygonal mirror, and the projections are brought into contact with the connecting portions of the rotary shaft to generate a fixing force. The optical scanning device according to claim 1, which is characterized in that. 4. A rotary polygon mirror having a plurality of mirror surfaces and having mounting holes formed therein, a sheet-like elastic member arranged along an inner wall surface of the mounting hole, and a connecting portion provided with slits. The rotation shaft of the motor that rotates the rotary polygon mirror with the connecting part inserted in the mounting hole and connected to the rotary polygon mirror sandwiching the elastic member, and the inner wall surface of the mounting hole are elastic. Fixing that connects the rotary polygon mirror and the rotary shaft by pressing the connecting part through the member and generating a fixing force in the corner direction between the mirror surfaces of the rotary polygon mirror along the radial direction of the rotary polygon mirror in the rotary polygon mirror. An optical scanning device comprising: a force generating member.